Known rotors for wind power generators have blades arranged radially to a rotational axis, which blades have a convex first surface facing the incoming wind and an opposite second surface having a planer convex profile which upon rotation is arranged in lee. Such blades have a significant inner volume that is defined by the two opposite convex surfaces, and they require a production process in which these opposite convex surfaces can be produced independently from one another. For adaptation of the profile of both convex surfaces to the local speed of the rotating blades the convex surfaces are usually arranged in a more complanate angle against the surface perpendicular to the rotational axis of the hub with increasing distance from the hub, e.g. from a precipitous positioning at the base of the blade to a flat positioning at the tip of the blade about parallel to a surface perpendicular to the hub.